I found a screen saver that models the BSOD (blue screen of death) and wanted to play a prank on a friend by disabling all but one Peripheral which I would be holding (a bluetooth mouse). I already know how to disable the trackpad when the mouse is present, but how do I disable the built in keyboard?

By the way, a link to the screen saver is XScreenSaver, and to make it compatible with Snow Leopard, see this arcticle.